The combined polymorphisms of interleukin-6-174GG genotype and interleukin-10 ATA haplotype are associated with a poor quality of life in patients with chronic hepatitis C

Purpose: Chronic hepatitis C (CHC) is associated with a decreased health-related quality of life (HRQOL). More recent studies have pointed toward a genetic basis of patient-reported quality of life outcomes. Taking into account that the influence of single-nucleotide polymorphisms (SNPs) on the HRQOL of CHC patients has not been studied, we investigated the combined IL10-1082G/A, - 819C/T, and - 592C/A SNPs, and IL6-174G/C SNP. We also evaluated the association between demographic, clinical, psychiatric, virological, and genetic variables with domains and summaries of HRQOL in CHC patients.

Methods: 132 consecutive CHC patients and 98 controls underwent psychiatric evaluation by using the Mini International Neuropsychiatric Interview. HRQOL was assessed by a generic questionnaire, the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), and by the specific Liver Disease Quality of Life Questionnaire (LDQOL). IL6 and IL10 polymorphisms were evaluated by Taqman SNP genotyping assay. Multivariate analysis was used to evaluate the associations.

Results: Major depressive disorder was associated with lower SF-36 and LDQOL scores in seven and ten domains, respectively. Diabetes and hypertension were also associated with reduced HRQOL. CHC patients carrying the combination of IL10 ATA haplotype/IL6-GG genotype had lower scores in the SF-36-physical functioning domain, and reduced scores in the LDQOL effects of liver disease on activities of daily living, quality of social interaction, and sexual function domains than the non-carriers of the combined haplotype/genotype.

Conclusion: This is the first study to demonstrate that combined IL6 high-producer GG genotype and IL10 low-producer ATA haplotype is associated with poorer HRQOL in CHC patients.